Scientists are unsure how many cells exist in the human body; estimates range from 10 to 100 trillion. But you once existed as a single cell - for about half an hour.

• 科学家现在并不确定人体内到底有多少个细胞；估计从10万亿-100万亿不等。但你曾经以一个微细胞的形式存在，时间大约为半小时。